This invention relates generally to a knife which automatically locks within a sheath upon insertion therein and which is releasable from the sheath through the squeezing of the handle of the knife.
When carrying a sheath knife, it is often desirable to have the knife securely locked in the sheath to prevent it from falling out inadvertently. This can be especially critical in adverse environmental conditions, such as those which may be faced by rescue workers, military and police personnel, back packers, SCUBA divers, etc. Providing means to lock the knife within the sheath have been developed, but most such designs require some special attention from a user when they are removed from the sheath, such as the depression of a certain tab, removal of a hasp or loop, etc., which can divert the user's attention from the task at hand. This can be particularly distracting in the case of SCUBA divers, where little or no light is available, and the diver's frame of reference may be skewed.
It would thus be desirable to provide a sheath-type knife which will cause the knife to automatically lock to the sheath once inserted therein, and which will also allow the knife to be quickly extracted from the sheath by the user through use of a natural, and comfortable motion which will minimize distraction to the user.
Other locking knife and sheath designs are known. For example, U.S. Pat. No. 5,123,167, issued to Kelley, discloses a knife with sheath engageable lock, wherein a flexible segment having a latch thereon engages with a recess provided in the sheath. U.S. Pat. No. 4,827,614, issued to Mitchell, discloses a locking tool handle holder arrangement having elongated springs provided in the handle. One end of each spring is fastened to the handle, while the other end includes an upturned portion recited as locking pin means. Activators are provided on the sides of the handle, and when squeezed inwardly towards one another, springs are forced downwardly by curved surfaces of activators. This causes a corresponding retraction of locking pin means, and consequently, unlocking of the handle from sheath. In the locking configuration, locking pin means extend through respective openings in the sheath. U.S. Pat. No. 2,793,434, issued to Wigington, discloses a knife having a pivoting catch for engaging a sheath. U.S. Pat. No. 2,391,574, issued to Housinger, discloses a knife having a spring arm with a pin thereon for engaging with a notch in a sheath.